A while ago I categorised the referendums at the federal level to see what voters were rejecting. It turns out it was centralisation; or the constitutional increase of power to the Commonwealth Government. Of the twenty-seven referendums for increased centralisation only three have passed. If these referendums are split between 1901-1951 and 1952-2006 a further imbalance appears.
In the failed referendums of the first half-century were three to give the Commonwealth control of industrial relations beyond s51xxxv. Those referendums are mentioned in the recent High Court case which the majority rejected as having effect on the final decision even though the dissent believed those failed referendums should have been taken into account.
The ratio of referendums put forward in the second half of the twentieth century is pretty low, and the failure rate is 100%. This suggests that the federal government has found different means to centralise power and the recent case on Workchoices is one example of this. The High Court has been highly accommodating to increases of constitutional power at the national level in the last fifty years making referendums less necessary in this area.